[MDEV-4621] select returns null for information_schema.statistics.collation field - Jira

Type: Bug
Status: Closed (View Workflow)
Priority: Critical
Resolution: Fixed
Affects Version/s: 10.0.2, 5.5.31, 5.1.67, 5.2.14, 5.3.12, 10.2(EOL), 10.3(EOL), 10.4(EOL), 10.5, 10.6, 10.7(EOL)
Fix Version/s: 10.2.42, 10.3.33, 10.4.23, 10.5.14, 10.6.6
Component/s: Information Schema
Labels:
- upstream-fixed
Environment:
Gentoo linux - Mariadb-5.5.31-log
Windows 7 - MariaDB-5.5.28

Hi,
I'm trying to get index info from information_schema.statistics
but, if I try to get collation field, it always returns null.

Test case

create table test.some_table (field1 int unsigned not null, field2 varchar(64), primary key (field1), key(field2));

/* collation with their correct value */

select * from information_schema.STATISTICS where table_name='some_table' and table_schema='test';

/* collation is null here */

select table_schema, table_name, index_name, column_name, collation

from information_schema.STATISTICS

where table_schema='test' and table_name='some_table';

/* collation (quoted) is null here */

select table_schema, table_name, index_name, column_name, `collation`

from information_schema.STATISTICS

where table_schema='test' and table_name='some_table';

relates to

MDEV-13756 Implement descending index: KEY (a DESC, b ASC)

links to

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